The present invention relates to a hinge device which can be reliably positioned at any of a variety of angles, more particularly, to a durable hinge device which is manually rotated.
The rapid development of portable computers has resulted in requirements for various hinge devices. A hinge device is desired for use in joining a display unit to a mainframe unit of a portable computer while reliably maintaining the two units in a fixed rotational position. Such a hinge device is disclosed in U.S. Pat. No. 5,632,066 and is illustrated in FIG. 5. The hinge device comprises a female connecting member 1, a male connecting member 2 and a plurality of fastening elements (not shown). The female connecting member 1 is fastened to a mainframe unit (not shown) of a portable computer (not shown) and includes a pair of parallel flat walls 12 and 14 and a pair of axle housings 16 connected between the two parallel flat walls 12 and 14. The male connecting member 2 is fastened to a display unit (not shown) of the portable computer and includes a pivot rod 23, a mounting plate 21 extending from an end of the pivot rod 23, and a neck 25 at an opposite end of the pivot rod 23. The neck 25 and the pivot rod 23 extend through the axle housings 16 of the female connecting member 1, the fastening elements being fastened to the neck 25 for holding the female connecting member 1 and the male connecting member 2 together. The pivot rod 23 of the male connecting member 2 fully contacts the inner face of the axle housings 16 of the female connecting member 1 without any intermediate, whereby the hinge device is held in position by a constant frictional force in all rotational positions. However, the frictional force lessens with use and after a time can not support positioning of the display unit relative to the mainframe unit.
The design of the hinge device results in a shortened lifespan for the hinge device, whereby the positioning of the mainframe unit relative to the display unit can not be ensured.